MANUFACTURING TECHNOLOGY OF FOUNDRY MODELS USING WOODWORKING WASTE

Abstract

The proposed scheme of the technological cycle of manufacturing foundry models from woodworking waste (sawdust). The existing model equipment is used as a master model. Based on the master model, an industrial model (form) is made, filled by compaction with a load of 2 MPa with a model mixture. The model mixture consists of woodworking waste and binding materials – BS‑40 resin, liquid glass, and G‑10 gypsum. It has a number of significant advantages: production of model sets in the shortest possible time with minimal costs for mechanical processing and without the use of additional equipment; lower cost compared to metal equipment; high wear resistance, which is not inferior to plastic models; high maintainability. Accuracy, stability of dimensions and configuration of the model during a long service life, minimal removal effort during molding; thanks to the unique anti-adhesion properties of the impregnation mixture, practically eliminates the need for additional equipment. The influence of the type and amount of binding material on the physical and mechanical properties of the models was analyzed. It is shown that application resins and sawdust in the ratio1.25:1 allow zoom-compressive strength up to 30kgf/cm2 and compressive strength to 0,0153 kgf/cm2. This is due to the fact that as a result of the use of resin, a stronger frame of the model is formed, which is almost not inferior to the strength characteristics of wood (pine). Considered the influence of the granulometry composition of the component model mixture – liquid glass and sawdust in a ratio of 2:1 on the physical and mechanical properties of the finished models. It showed that increasing the liquid glass and sawdust mixture fraction from 0,25 to 2 mm increases the compressive strength limit by 3 times.